Renal Emergencies Flashcards
What is AKI?
Sudden loss of kidney function causing hyperuraemia, and retention of other nitrogenous waste products, and dysregulation of extracellular volume and electrolytes.
What are the 3 classes of causes of AKI?
Pre-renal
Renal
Post-renal
How is AKI often detected and monitored?
Seriel serum creatinine readings
Urine output
eGFR
What are the main pre-renal causes of AKI?
- Hypovolaemia - mainly sepsis or fluid depletion (vomiting/diarrhoea), anaphylaxis, cardiogenic shock
- Oedematous states e.g. HF
- CVS - HF, arrythmias
- Hypoperfusion of kidneys e.g. by drugs, artery occlusion
Which drugs can cause AKI by renal hypoperfusion?
NSAIDs
COX-2 inhibitors
ACE-Inhibitors
ARBs
What are the main renal causes of AKI?
- Glomerular disease
- Tubular injury
- Acute interstitial nephritis
- Vasculitis
- Eclampsia
What are the post renal causes of AKI?
Outflow obstruction due to:
- Renal calculi
- Blood clot
- Urethral stricture
- BPH/Ca Prostate
- Bladder tumour
- Pelvic fibrosis
How common is AKI?
~15% of adults admitted to hospital develop AKI (estimation)
Why is a good hx important when giving iodinated contrast agents?
Certain factors increase the risk of AKI following use to iodinated contrast agents.
Who is at higher risk of AKI following use of iodinated contrast?
- CKD
- Diabetes with CKD
- HF
- Age over 75
- Hypovolaemia
What are the 2 cliinical features of AKI?
- Oligouria/anuria
- Rise in serum creatinine
What rise in serum creatinine is indicative of AKI?
- Rise of >26 nanomol/L in 48 hours
- >50% rise i.e. 1.5x baseline within last 7 days
A pt presents with AKI. They suddenly became anuric earlier today. Where is the cause most likely to be?
Outflow tract obstruction or renal artery occlusion
A pt with AKI is likely to be in fluid retention. What signs may there be of this on examination?
- Hypertension
- Raised JVP
- Pulmonary oedmea
- Peripheral oedma
Which antibiotics are nephrotoxic and therefore have the potential to cause AKI?
Aminoglycosides e.g. Gentamicin
A patient presents with haematuria. Where might the blood have originate from?
Kidney Ureters Bladder Urethra Prostate Vagina
What are the different types of haematuria?
Visible and non-visible
How might non-visible haematuria e picked up?
Either incidentally, or on dipstick following presentation with LUTS or upper UTS.
Name the top 3 causes of non-visible haematuria.
UTI
BPH
Urinary calculi
What features would be evident O/E of a patient with haematuria that would suggest a renal cause?
Hypertension
Altered renal funciton on Ix
Proteinura
Mass in renal angle
Is anticoagulation likely to be the cause of haematuria?
No but it can provoke or worsen it.
How should a patient with haematuria be investigated?
Exclude transient causes such as UTI.
Check U&Es and BP
Urine dip
Send urine for microscopy
All visible haematuria should be Ix to exclude malignancy
What is an interstitial nephritis?
Renal failure associated with inflammation of the renal interstitium
Which cells in the kidney have the endocrine function? What do they produce?
The interstitial fibrblast cells. They produce erythropoietin and prostaglandins.
What are the 2 main forms of interstitial nephriitides?
Acute interstitial nephritis
Chronic tubulointerstitial nephritis
What is the most common cause of acute interstitial nephritis?
Drugs/nephrotoxins.
Which drugs are implicted in acute nephritis?
-Penicillins
-Cephlosporins
-Co-trimoxazole
Most abx tbh
NSAIDs
Loop and thiazide diuretics
What is acute interstitial nephritis?
AKI/renal failure presenting in association with systemic infection, drug reaction, sarcoidosis, Sjogren’s syndrome or uveitis.
